ADJUSTMENT OF A pH ELECTRODE CARBON REGION

ABSTRACT

An embodiment provides a method for modifying a carbon region on a boron-doped diamond electrode surface, comprising: placing a boron-doped diamond electrode surface in an aqueous solution, wherein the aqueous solution comprises an ionic treatment solution; applying a voltage difference across the boron-doped diamond electrode surface; and modifying a carbon region on an area of the boron-doped diamond electrode surface, wherein the modifying is responsive to application of the voltage while the boron-doped diamond electrode surface is in the aqueous solution, wherein the modification continues until a desired signal of the carbon region is reached. Other aspects are described and claimed.

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 63/016,708, filed on Apr. 28, 2020, and U.S. patent applicationSer. No. 17/126,617, filed on Dec. 18, 2020, both of which are entitled“ADJUSTMENT OF A pH ELECTRODE CARBON REGION,” and the contents of bothare incorporated by reference herein.

FIELD

This application relates generally to pH measurement of an aqueoussample, and, more particularly, to pH electrodes with a carbon region.

BACKGROUND

Ensuring water quality is critical to the health and well-being ofhumans, animals, and plants, which are reliant on water for survival.One parameter of water that may be measured is the pH. The measurementof pH of an aqueous sample is critical in a number of industries such aspharmaceuticals, biomedical, water supply, and other manufacturingfields. Measurement of pH may allow for proper treatment of water orensuring proper water quality for sensitive purposes, and allows foridentifying the overall quality of the water. One method to measure pHin an aqueous sample includes the use of electrodes which requireconstant maintenance and calibration of the pH measurement system.

BRIEF SUMMARY

In summary, one embodiment provides a method for modifying a carbonregion on a boron-doped diamond electrode surface, comprising: placing aboron-doped diamond electrode surface in an aqueous solution, whereinthe aqueous solution comprises an ionic treatment solution; applying avoltage difference across the boron-doped diamond electrode surface; andmodifying a carbon region on an area of the boron-doped diamondelectrode surface, wherein the modifying is responsive to application ofthe voltage while the boron-doped diamond electrode surface is in theaqueous solution, wherein the modification continues until a desiredsignal of the carbon region is reached.

Another embodiment provides a device for modifying a carbon region on aboron-doped diamond electrode surface, comprising: a boron-doped diamondelectrode surface; at least one other electrode; an aqueous solution; avoltage generator; a processor; a memory device that stores instructionsexecutable by the processor to: place a boron-doped diamond electrodesurface in an aqueous solution, wherein the aqueous solution comprisesan ionic treatment solution; apply a voltage difference across theboron-doped diamond electrode surface; and modify a carbon region on anarea of the boron-doped diamond electrode surface, wherein the modifyingis responsive to application of the voltage while the boron-dopeddiamond electrode surface is in the aqueous solution, wherein themodification continues until a desired signal of the carbon region isreached.

A further embodiment provides a system for modifying a carbon region ona boron-doped diamond electrode surface, comprising: a volume of aqueoussolution; a voltage generator; a boron-doped diamond electrode surface;and a storage device having code stored therewith, the code beingexecutable by the processor and comprising: code that places aboron-doped diamond electrode surface in an aqueous solution, whereinthe aqueous solution comprises an ionic treatment solution; code thatapplies a voltage difference across the boron-doped diamond electrodesurface; and code that modifies a carbon region on an area of theboron-doped diamond electrode surface, wherein the modifying isresponsive to application of the voltage while the boron-doped diamondelectrode surface is in the aqueous solution, wherein the modificationcontinues until a desired signal of the carbon region is reached.

The foregoing is a summary and thus may contain simplifications,generalizations, and omissions of detail; consequently, those skilled inthe art will appreciate that the summary is illustrative only and is notintended to be in any way limiting.

For a better understanding of the embodiments, together with other andfurther features and advantages thereof, reference is made to thefollowing description, taken in conjunction with the accompanyingdrawings. The scope of the invention will be pointed out in the appendedclaims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A illustrates a schematic diagram of adjustment of a pH electrodecarbon region in an example contact arrangement embodiment. FIG. 1Billustrates a schematic diagram of adjustment of a pH electrode carbonregion in an example non-contact arrangement embodiment.

FIG. 2 illustrates a flow diagram of adjustment of a pH electrode carbonregion in an example embodiment.

FIG. 3 illustrates a current—voltage relationship over time of a pHelectrode carbon region in an example embodiment.

FIG. 4 illustrates an example of computer circuitry.

DETAILED DESCRIPTION

It will be readily understood that the components of the embodiments, asgenerally described and illustrated in the figures herein, may bearranged and designed in a wide variety of different configurations inaddition to the described example embodiments. Thus, the following moredetailed description of the example embodiments, as represented in thefigures, is not intended to limit the scope of the embodiments, asclaimed, but is merely representative of example embodiments.

Reference throughout this specification to “one embodiment” or “anembodiment” (or the like) means that a particular feature, structure, orcharacteristic described in connection with the embodiment is includedin at least one embodiment. Thus, appearances of the phrases “in oneembodiment” or “in an embodiment” or the like in various placesthroughout this specification are not necessarily all referring to thesame embodiment.

Furthermore, the described features, structures, or characteristics maybe combined in any suitable manner in one or more embodiments. In thefollowing description, numerous specific details are provided to give athorough understanding of embodiments. One skilled in the relevant artwill recognize, however, that the various embodiments can be practicedwithout one or more of the specific details, or with other methods,components, materials, et cetera. In other instances, well-knownstructures, materials, or operations are not shown or described indetail. The following description is intended only by way of example,and simply illustrates certain example embodiments.

The measurement of the pH of water or other aqueous solutions or samplesis common and allows for determination of the quality or othercharacteristics of the aqueous solution. Conventional pH electrodes formeasurement of pH may be constructed using fragile, thin glass. Thisglass breaks easily leading to higher replacement and maintenance costs.The possible breakage of glass pH electrodes may also limit their use infood and beverage applications. Conventional pH electrodes also may have“alkali errors.” These errors arise from interfering ions such as sodiumand potassium affecting the pH response at high pH values. A commercialneed exists for a robust pH measurement electrode that requires lessmaintenance while maintaining measurement of pH in sample containingheavy metals or a low conductivity sample, especially in an unbuffered,aqueous sample.

Another method of measuring pH of an aqueous sample uses a lasermachined boron-doped diamond material to create an electrode sensorcapable of measuring pH. Laser machining of the boron-doped diamondcreates pH sensitive quinone-like structures on the boron-doped diamondmaterial, due to the introduction of sp² carbon. These laser machinedareas or pits may constitute a single spot (See U.S. patent applicationSer. No. 16/459,300) or be in an array pattern. In other words, thelaser machined areas may be a series of spots across a surface. Thelaser machining of these multiple spots may be challenging. For example,an array of laser machines pits across a surface requires using thelaser repeatedly across the surface.

A boron-doped diamond pH electrode may give greater accuracy, especiallyimproved accuracy in samples with low conductivity or low buffercapacity. boron-doped diamond pH electrodes may measure pH in all pHranges including an environmentally relevant range of pH 4 to 11. Bettercontrol over quinone-like structure is required as the quinone-likestructure density and nature may impact accuracy in low conductive andlow buffer capacity solutions. What is needed is a method and system toadjust the carbon region or sp² carbon region upon a boron-doped diamondpH electrode.

Accordingly, the systems and methods as described herein may be used toadjust or tune an sp² carbon region of a boron-doped diamond electrode.Reference to electrode throughout refers to a boron-doped diamondsurface, which may be packaged into electrode format or left in waferformat. The boron-doped diamond electrode may be placed in an aqueoussolution. The boron-doped diamond electrode may have a carbon region orsp² carbon. The carbon region may be laser machined upon the boron-dopeddiamond surface. The laser machining may occur before the adjustment ofthe boron-doped diamond. In an embodiment, a voltage may be passedthrough the boron-doped diamond in an electrode format (contact method),or through a non-contact method such as a bipolar arrangement, whereboron-doped diamond material (or wafer) is placed in the aqueoussolution. In an embodiment, the system and method may adjust or tune asp² component of the boron-doped diamond surface. The modification ofthe sp² diamond material may be performed using the contact ornon-contact method. The adjustment may reduce or modify overallquinone-like structures and/or their density. For clarity, the termmodification may be used for adjustment, removal, tuning, or the like,the quinone-like structures and/or the density of the quinone structureson the boron-doped diamond surface. This may be in a boron-doped diamondpH electrode format. The reduction or modification of quinone-likestructure/density may improve overall unbuffered pH performance. In anembodiment, the system and method may apply a voltage across boron-dopeddiamond electrode until a desired result is achieved. The system andmethod may monitor a pH signal or a peak in current from the electrodeundergoing adjustment. The adjusted electrode may determine a pH byidentifying an electrical potential of an aqueous sample, or may be usedto measure an electrochemical component of a sample.

The electrode may have a carbon region and a pH sensitive carbon region.For example, the electrode may be a boron-doped diamond electrode with aplurality of sp² carbon regions. The pH sensitive carbon region may belaser machined. The laser micromachined electrode surface may comprisesp² carbon, as well as spa carbon(diamond)-doped with elements likeboron (boron-doped diamond). The pH sensitive carbon region may be a sp²carbon region that is included on a boron doped diamond-based pHelectrode. Being included may mean that the sp² carbon region isintroduced into, integrated into, contained within, laser micro machinedinto, or otherwise integrated into the boron doped diamond surface. Inother words, while the sp² carbon region and the boron doped diamond areintegrated into the same electrode, they are chemically differentregions of the electrode. The sp² carbon region may have oxidized carbonstructures. The oxidized carbon structure may have quinone orquinone-like groups. The system and method described herein may providean adjustment of the quinone, or quinone-like group density of the sp²region of the boron-doped diamond electrode.

The use of boron-doped diamond serves as a better electrode materialthan other carbon-based or metallic materials (e.g., silver, gold,mercury, nickel, etc.) because these materials may be moreelectrocatalytically active, and may generate interfering signalscontributing to the errors in the measurement of pH.

The illustrated example embodiments will be best understood by referenceto the figures. The following description is intended only by way ofexample, and simply illustrates certain example embodiments.

Referring now to FIG. 1A-B, an embodiment may modify the quinone-likedensity of a boron-doped diamond electrode. For example, FIG. 1Aillustrates a contact arrangement. In a contact arrangement, aboron-doped diamond electrode may be electrically coupled and in anaqueous solution. For example, a sp² carbon region with quinone-likegroups may be laser machined on a boron-doped diamond electrode. Thelaser machining may occur prior to an adjustment or tuning of the pHboron-doped diamond electrode. In an embodiment, the boron-doped diamondelectrode may be placed in a volume of aqueous solution. In anembodiment, a voltage may be applied across the boron-doped diamondelectrode within the aqueous solution. In an embodiment, there may be aplurality of boron-doped diamond electrodes in a volume of aqueoussolution. The voltage may be applied until a desired density ofquinone-like structures remain on the boron-doped diamond electrode. Inan embodiment, the boron-doped diamond electrode used in a finalapplication may be connected at the cathode or the anode. In anembodiment, the opposite pole may be a boron-doped diamond electrode, oran electrode made of a different material. In this manner, a poleselected for the boron-doped diamond electrode may have an effect on themodification of an electrode based on either a cathode or an anodeposition. In an embodiment, the length of time a voltage is applied orthe amplitude of the voltage may be determined by measuring a pH peak orother current peak from the boron-doped diamond electrode in the bath ofaqueous solution, or taking the electrode out at regular time intervalsand checking the response in another solution. In other words, anelectrode may be removed from a solution for modification and placed inanother solution to check electrode performance. As another example,FIG. 1B illustrates a non-contact or bipolar arrangement. In anon-contact arrangement, the boron-doped diamond may be in the aqueoussolution. In other words, a non-contact arrangement involves theplacement of a boron-doped diamond sample or wafer between the drivingelectrodes, where a voltage is applied directly to the drivingelectrodes, not the boron-doped diamond. A non-contact or bipolararrangement, is where the boron-doped diamond electrode or wafer to betreated is placed between two driving electrodes generating possibleoxidizing species required for the removal/modification to occur. Theboron-doped diamond sample or wafer may then be placed in electrodeformat after non-contact treatment, to create a boron-doped diamond pHelectrode.

The boron-doped diamond electrode may measure pH of a sample. In anembodiment, an electrode may be laser micromachined or machined tointroduce an array of pits into the electrode surface or face. In anembodiment, a combination of pits may create a pattern upon theelectrode. The laser machining may introduce sp² carbon upon theelectrode. The sp² carbon may include quinone or quinone-like groupswhich may undergo proton-coupled electron transfer. In an embodiment,the laser machined electrodes may be used to perform electrochemicalmeasurements to measure a pH response on the electrode in which theobserved current—voltage peak may be indicative of a pH of a sample. Inan embodiment, the aqueous solution and/or the applied voltage mayremove quinone-like structures from the boron-doped diamond electrode.The system and method may remove, etch, or adjust sp² carbon and modifythe surface termination including the associated oxygen containingfunctional groups over time. In an embodiment, the time of appliedvoltage, the voltage amplitude, type of aqueous solution, saltconcentration of aqueous solution, or the like may be altered to achievea desire result. The adjustment may be performed manually, controlled bya system, and/or be fully automated.

In an embodiment, a boron-doped diamond pH electrode may operate in aNernstian manner across a pH range in a buffered solution. Suchproperties may be present in a boron-doped diamond electrode before orafter adjustment. In an unbuffered solution, a boron-doped diamond pHelectrode may deviate from an expected theoretical response. A deviationmay be linked to an amount of sp² carbon present and/or the amount ofquinone-like groups on an electrode surface. Thus, control of carbonregion and associated density of quinone-like structures may be criticalto the efficient manufacture of an accurate electrode. The system andmethod disclosed may provide better manufacturing of a suitableboron-doped diamond pH electrode with sp² regions with quinone-likestructures.

Referring to FIG. 2 , an example embodiment to adjust a boron-dopeddiamond electrode with a carbon region is illustrated. At 201, in anembodiment, a boron-doped diamond electrode may be placed in an aqueoussolution. The boron-doped diamond electrode may be placed into anaqueous solution either manually or in an automated manner. In anembodiment, there may be a plurality of boron-doped diamond electrodesin an aqueous solution bath or volume. Multiple boron-doped diamondelectrodes may be used to complete a circuit through the aqueoussolution or multiple boron-doped diamond electrodes may be adjusted atthe same time in a volume of aqueous solution.

In an embodiment, the aqueous solution may be an acid, base or neutralsolution. The aqueous solution may comprise a source of ions such as anacid, strong, acid, base, or neutral solution which may be buffered orunbuffered. The source of ions may be referred to an ionic treatmentsolution. It may be a strong or weak acid. The acid may be aconcentrated acid solution. The acid may be greater than or equal to0.01 M. The acid may be sulfuric acid, nitric acid, hydrochloric acid,citric acid, acetic acid or the like. It may be a base solution. Thebase may be greater than or equal to 0.01 M. The base may be potassiumhydroxide, sodium hydroxide, ammonia, methylamine or the like. It may bea salt solution. The salt solution may be any pH, including neutral. Thesolution may be buffered or unbuffered. The salt solution may bepotassium nitrate, potassium chloride, potassium sulphate, or the like.An aqueous solution composition, concentration, and length of time inthe aqueous solution may be selected based upon the application forwhich the boron-doped diamond pH electrode is adjusted for use. Theaqueous solution components, as well as an applied voltage, may modifysp² carbon from the boron-doped diamond electrode.

At 202, in an embodiment, a voltage may be applied across theboron-doped diamond electrode in the aqueous solution volume. In anembodiment, the voltage may be equal to or greater than 5 volts withrespect to ground. In an embodiment, the voltage difference applied maybe equal to, around, or greater than 30 volts with respect to ground. Inan embodiment, the voltage time, duration, or the like may be altered.The system and method may follow preprogrammed instructions, inputparameters from a user or database, or the like. The voltage may beapplied using a voltage generator. The voltage may be applied across theboron-doped diamond electrode selected for tuning, across the aqueoussolution volume, and/or another electrode within the aqueous solutionvolume to complete the circuit. The other electrode may be anotherboron-doped diamond electrode, another type of electrode, or anyconductive material.

At 203, in an embodiment, a carbon region of a boron-doped diamondelectrode may be removed. In an embodiment, the removal/modification ofa pH active carbon region may be referred to as adjusting, tuning, oretching the carbon region. This carbon region may be pH sensitive. In anembodiment, the electrochemistry of the method and system may allow ageneration of radical species such as sulfates, hydroxyl, nitrates, orthe like, dependent on the aqueous solution used, near or around theelectrode surface. The radical species may assist in theremoval/modification of sp² at the boron-doped diamond electrode.Additionally, or alternatively, localized heating at the electrodesurface may assist in sp² removal/modification.

In an embodiment, a higher quinone surface coverage of a boron-dopeddiamond electrode may lead to increased pH errors in unbuffered, aqueoussolutions. The system and method herein may provide a systemicremoval/modification of quinone-like groups. The removal/modification ofquinone-like groups may improve boron-doped diamond pH electrodeperformance. The increase in boron-doped diamond pH electrodeperformance may allow for a more accurate pH measurement in unbufferedconditions. In other words, the sp² component may be tuned or adjustedto ensure some of the quinone-like groups remain, as these quinone-likegroups may detect a pH signal.

At 204, the system and method may determine if a desired pH signal hasbeen detected. In an embodiment, the system and method may use atechnique as illustrated in FIG. 3 . for determination. For example, avoltage may be applied until a peak current of a desired amplitude or apH signal is measured. An example of such method illustrated in FIG. 3of a current—voltage relationship over time of an adjustment of a pHboron-doped diamond electrode. In other words, as voltage is applied toa boron-doped diamond electrode in an ionic treatment solution overtime, the pH sensitive sp² region may be modified, and the pH signal mayalso be reduced. In an embodiment, a peak of the current—voltagerelationship may correlate to a pH value. In an embodiment, a rate ofremoval/modification of sp² carbon may be determined. The rate ofremoval/modification may be determined by measuring a pH signal overtime during a boron-doped diamond electrode adjustment. The rate ofremoval/modification may be controlled by the system. In other words,the system may use a rate to determine the efficacy of theremoval/modification process.

If the system determines a desired pH signal has not been reached, thesystem may continue to apply a voltage across the boron-doped diamondelectrode being adjusted within the aqueous solution volume. In anembodiment, the method and system may adjust an amplitude, duration,and/or waveform to achieve a desired pH signal. In other words, thesystem may adjust voltage parameters to achieve a desired pH signal.However, if, at 204 a desired pH signal has been reached, the system maystop applying voltage at 205.

Measurement of a pH signal may be at periodic intervals set by the useror preprogrammed frequencies in the system. A measurement of the pHsignal may be an output upon a device in the form of a display,printing, storage, audio, haptic feedback, or the like. Alternatively,or additionally, the output may be sent to another device through wired,wireless, fiber optic, Bluetooth®, near field communication, or thelike. An embodiment may use an alarm to warn of a measurement outsideacceptable or desired levels. An embodiment may use a system to shutdown a voltage or alter a voltage within unacceptable parameters,limits, or thresholds. For example, a measuring device may beoperatively coupled to a voltage generator.

In an embodiment, the system may detect when a volume of aqueoussolution becomes diluted, low on volume, depleted, or the like. Forexample, the system may receive an alert of a volume of aqueous solutionoutside of specification and provide an alert or take action to flush orreplenish the volume of aqueous solution. Additionally or alternatively,the system may output an alarm, log an event, or the like.

In an embodiment, the performance of the method and system of theadjustment of a boron-doped diamond electrode may be communicated and/orstored. The system may connect to a communication network. The systemmay alert a user or a network. This alert may occur whether aboron-doped diamond electrode is adjusted properly or improperly. Analert may be in a form of audio, visual, data, storing the data to amemory device, sending the output through a connected or wirelesssystem, printing the output or the like. The system may log informationsuch as the measurement location, a corrective action, geographicallocation, time, date, number of measurement/adjustment cycles, pHsignal, current—voltage plots, or the like. The alert or log may beautomated, meaning the system may automatically output whether acorrection was required or not. The system may also have associatedalarms, limits, or predetermined thresholds. For example, if aboron-doped diamond electrode adjustment falls below a threshold orlimit. Alarms or logs may be analyzed in real-time, stored for lateruse, or any combination thereof.

In an embodiment, the electrodes may be fully or at least partiallydisposed in the aqueous solution volume. For example, if the aqueoussolution is introduced into a chamber having one or more electrodes, theaqueous solution may at least partially cover the one or moreelectrodes. As another example, the one or more electrodes may bepartially disposed within the chamber and/or aqueous solution with theother portion of the electrode outside the chamber and/or aqueoussolution. Thus, when the aqueous solution is introduced into the chamberit may only cover the portion of the electrodes that are within thechamber. The aqueous solution may be in a chamber, beaker, or any vesselof a material suitable for aqueous solution.

The various embodiments described herein thus represent a technicalimprovement to conventional methods, such as high temperature acidcleaning, providing more precise control over the modification processfor adjusting a pH sensitive boron-doped diamond electrode. Using thetechniques as described herein, an embodiment may use a method andsystem for an adjusting sp² carbon regions and/or quinone-like densityon a boron-doped diamond electrode. This is in contrast to conventionalmethods with limitations mentioned above. Such techniques provide abetter method to construct an instrument for pH measurement.

While various other circuits, circuitry or components may be utilized ininformation handling devices, with regard to an instrument foradjustment of a pH electrode carbon region according to any one of thevarious embodiments described herein, an example is illustrated in FIG.4 . Device circuitry 10′ may include a measurement system on a chipdesign found, for example, a particular computing platform (e.g., mobilecomputing, desktop computing, etc.) Software and processor(s) arecombined in a single chip 11′. Processors comprise internal arithmeticunits, registers, cache memory, busses, I/O ports, etc., as is wellknown in the art. Internal busses and the like depend on differentvendors, but essentially all the peripheral devices (12′) may attach toa single chip 11′. The circuitry 10′ combines the processor, memorycontrol, and I/O controller hub all into a single chip 11′. Also,systems 10′ of this type do not typically use SATA or PCI or LPC. Commoninterfaces, for example, include SDIO and I2C.

There are power management chip(s) 13′, e.g., a battery management unit,BMU, which manage power as supplied, for example, via a rechargeablebattery 14′, which may be recharged by a connection to a power source(not shown). In at least one design, a single chip, such as 11′, is usedto supply BIOS like functionality and DRAM memory.

System 10′ typically includes one or more of a WWAN transceiver 15′ anda WLAN transceiver 16′ for connecting to various networks, such astelecommunications networks and wireless Internet devices, e.g., accesspoints. Additionally, devices 12′ are commonly included, e.g., atransmit and receive antenna, oscillators, PLLs, etc. System 10′includes input/output devices 17′ for data input and display/rendering(e.g., a computing location located away from the single beam systemthat is easily accessible by a user). System 10′ also typically includesvarious memory devices, for example flash memory 18′ and SDRAM 19′.

It can be appreciated from the foregoing that electronic components ofone or more systems or devices may include, but are not limited to, atleast one processing unit, a memory, and a communication bus orcommunication means that couples various components including the memoryto the processing unit(s). A system or device may include or have accessto a variety of device readable media. System memory may include devicereadable storage media in the form of volatile and/or nonvolatile memorysuch as read only memory (ROM) and/or random access memory (RAM). By wayof example, and not limitation, system memory may also include anoperating system, application programs, other program modules, andprogram data. The disclosed system may be used in an embodiment of aninstrument for adjustment of a pH electrode carbon region.

As will be appreciated by one skilled in the art, various aspects may beembodied as a system, method or device program product. Accordingly,aspects may take the form of an entirely hardware embodiment or anembodiment including software that may all generally be referred toherein as a “circuit,” “module” or “system.” Furthermore, aspects maytake the form of a device program product embodied in one or more devicereadable medium(s) having device readable program code embodiedtherewith.

It should be noted that the various functions described herein may beimplemented using instructions stored on a device readable storagemedium such as a non-signal storage device, where the instructions areexecuted by a processor. In the context of this document, a storagedevice is not a signal and “non-transitory” includes all media exceptsignal media.

Program code for carrying out operations may be written in anycombination of one or more programming languages. The program code mayexecute entirely on a single device, partly on a single device, as astand-alone software package, partly on single device and partly onanother device, or entirely on the other device. In some cases, thedevices may be connected through any type of connection or network,including a local area network (LAN) or a wide area network (WAN), orthe connection may be made through other devices (for example, throughthe Internet using an Internet Service Provider), through wirelessconnections, e.g., near-field communication, or through a hard wireconnection, such as over a USB connection.

Example embodiments are described herein with reference to the figures,which illustrate example methods, devices and products according tovarious example embodiments. It will be understood that the actions andfunctionality may be implemented at least in part by programinstructions. These program instructions may be provided to a processorof a device, e.g., a measurement device such as illustrated in FIG.1A-B, or other programmable data processing device to produce a machine,such that the instructions, which execute via a processor of the device,implement the functions/acts specified.

It is noted that the values provided herein are to be construed toinclude equivalent values as indicated by use of the term “about.” Theequivalent values will be evident to those having ordinary skill in theart, but at the least include values obtained by ordinary rounding ofthe last significant digit.

This disclosure has been presented for purposes of illustration anddescription but is not intended to be exhaustive or limiting. Manymodifications and variations will be apparent to those of ordinary skillin the art. The example embodiments were chosen and described in orderto explain principles and practical application, and to enable others ofordinary skill in the art to understand the disclosure for variousembodiments with various modifications as are suited to the particularuse contemplated. Thus, although illustrative example embodiments havebeen described herein with reference to the accompanying figures, it isto be understood that this description is not limiting and that variousother changes and modifications may be affected therein by one skilledin the art without departing from the scope or spirit of the disclosure.

What is claimed is:
 1. A device for modifying a carbon region on aboron-doped diamond electrode surface, comprising: a boron-doped diamondelectrode surface; at least one other electrode; an aqueous solution; avoltage generator; a processor; a memory device that stores instructionsexecutable by the processor to: place a boron-doped diamond electrodesurface in an aqueous solution, wherein the aqueous solution comprisesan ionic treatment solution; apply a voltage difference between twodriving electrodes and across the boron-doped diamond electrode surface,wherein the voltage difference is applied directly to the two drivingelectrodes, wherein the boron-doped diamond electrode surface is placedbetween the two driving electrodes in a non-contact arrangement withoutcontacting the two driving electrodes; and modify a carbon region on anarea of the boron-doped diamond electrode surface, wherein the modifyingis responsive to application of the voltage difference while theboron-doped diamond electrode surface is in the aqueous solution,wherein the modification continues until a desired signal of the carbonregion is reached.
 2. The device of claim 1, wherein the ionic treatmentsolution comprises ions and is selected from the group consisting of:sulfuric acid, nitric acid, hydrochloric acid, citric acid, acetic acid,potassium hydroxide, sodium hydroxide, ammonia, methylamine, potassiumnitrate, potassium sulfate, and potassium chloride.
 3. The device ofclaim 1, wherein the carbon region is a sp² carbon region.
 4. The deviceof claim 1, wherein the modifying alters at least one of: oxidizedcarbon structures and quinone-like groups.
 5. The device of claim 1,wherein the voltage difference applied is equal to or greater than 5V asmeasured against ground.
 6. The device of claim 1, wherein the appliedvoltage difference generates radical species.
 7. The device of claim 1,further comprising measuring a current-voltage relationship of thecarbon region during modification, wherein the measuring is performedfor a duration until a predetermined modification completes.
 8. Thedevice of claim 7, wherein a measured current at a predetermined appliedvoltage decreases with modification of the carbon region.
 9. The deviceof claim 7, wherein a peak of the current-voltage relationshipcorrelates to a pH value.
 10. A system for modifying a carbon region ona boron-doped diamond electrode surface, comprising: a volume of aqueoussolution; a voltage generator; a boron-doped diamond electrode surface;and a storage device having code stored therewith, the code beingexecutable by the processor and comprising: code that places aboron-doped diamond electrode surface in an aqueous solution, whereinthe aqueous solution comprises an ionic treatment solution; code thatapplies a voltage difference between two driving electrodes and acrossthe boron-doped diamond electrode surface, wherein the voltagedifference is applied directly to the two driving electrodes, whereinthe boron-doped diamond electrode surface is placed between the twodriving electrodes in a non-contact arrangement without contacting thetwo driving electrodes; and code that modifies a carbon region on anarea of the boron-doped diamond electrode surface, wherein the modifyingis responsive to application of the voltage difference while theboron-doped diamond electrode surface is in the aqueous solution,wherein the modification continues until a desired signal of the carbonregion is reached.